Mechanical behavior of bolted joints in precast segmental concrete structures subjected to impact loads

An increasing number of precast segmental concrete structures are being adopted in civil engineering applications. During their service life, these structures may be subjected to accidental impact loads not typically accounted for in the design, such as rockfalls and vehicle or vessel collisions. Previous studies indicate that the joints in precast segmental structures are critical and vulnerable regions. In this study, the mechanical behavior and failure modes of bolted precast segmental joints were investigated through a combination of low‐velocity drop weight impact tests and numerical simulations. Digital image correlation and high‐speed photography were employed to capture the dynamic responses of the joints. The study investigated the influence of impact energy, impact location, bolt modeling approach, and specimen width. It was found that failure modes under outer‐side impacts are highly sensitive to joint width, characterized by brittle fracture at the minimum thickness section in narrow joints. Conversely, inner‐side impacts consistently resulted in localized concrete damage around the handhole. The failure pattern resulting from cumulative lower‐energy impacts was observed to be similar to that of a single high‐energy impact. Additionally, the high‐strength bolts were found to remain in an elastic state during the impacts. Furthermore, the choice of bolt modeling approach and specimen width significantly influences the numerical simulation results.